Core C will store the libraries, and any individual constructs built for this consortium, as bacterial glycerol stocks. Furthermore, the goal of our consortium is to make this technology as open source as possible, and therefore this Core will handle all external requests for shRNAmir libraries or individual constructs. LIAI has an RNAi Center with an excellent infrastructure already in place for large scale library handling, storing, and disseminating. Core C has 3 roles: 1. Storage of the thousands of shRNAmir constructs. 2. Dissemination of libraries through the U19 groups, as bacterial clone replicates. 3. Dissemination of libraries and constructs throughout the NIH IMVC.